Neurocardiogenic syncope (patient information)
Overview
Neurocardiogenic syncope is also known known as vasovagal syncope, reflex syncope, and neurally mediated syncope. It refers to a fainting spell that usually occurs in response to a specific trigger. The syncope, or fainting generally occurs due to a momentary loss of blood flow to the brain, which deprives the brain of oxygen. The fainting spell is involuntary, and there is a rapid recovery afterwards. Episodes of dizziness or lighteheadedness without losing consciousness is called pre-syncope. Injuries can occur as a risk of syncope or fainting, and syncope can signal an impending cardiac arrest. It is important to distinguish neurocardiogenic syncope from other causes of fainting or loss of consciousness, such as low blood sugar levels in diabetics, seizure, or heart attack. Neurcardiogenic syncope is essentially a momentary failure of the brain and the cardiovascular system to communicate with each other, causing a fainting spell in response to a particular trigger. Neurocardiogenic syncope is usually benign, however one should see a doctor following a faiting spell especially if it is the first one.
What are the triggers for neurocardiogenic Syncope?
- Seeing blood or losing blood
- Pain
- Emotional stress or anxiety
- Prolonged standing
- Heat
- Physical exertion
- Defecation or urination
- Standing up suddenly
- Coughing spells
What are the symptoms of neurocardiogenic syncope?
There may be symptoms leading up to the fainting spell, consisting of:
- Nausea
- Sweating
- Lightheadedness
- Tingling or numbness in the arms and legs
- Blurry vision
- Headaches
- Palpitations or "racing heartbeat"
- Pale in apperarance
- Warmth
- Visual "grayout"
- Abdominal discomfort
What causes neurocardiogenic syncope
Neurocardiogenic syncope occurs when the part of the nervous system that regulates heart rate and blood pressure temporarily malfunctions. Usually in response to some sort of trigger such as fear or the sight of blood, the heart rate slows down, and the blood vessels in the legs dilate. This causes blood to pool in the lower region of the body, and therefore a lack of blood and oxygen to the brain which causes fainting. This is similar to what happens when one feels faint after suddenly standing up. When a person faints, gravity causes blood flow to to the brain to be restored and the person gains consciousness.
Who is at highest risk
Neurocardiogenic syncope is most common in children and young adults, and commonly people grow out of this condition as they reach adulthood. It also tends to occur in persons who have a family history of fainting spells. It is thought to affect persons who have a genetic predisposition towards poor resistance in the blood vessels of the lower extremities, causing blood to pool away from the brain in response to certain situations.
When to seek urgent medical care
Syncope or fainting in the setting of certain criteria warrant seeking medical care, and may be a sign of a serious disorder.
- If the syncope occurs while exercising
- If it is associated with heart palpitations or irregularities in the heartbeat, or if the person has a known cardiac arrythmia
- If it occurs in an individual with a family history of recurrent syncope or death
- If the syncope is associated with seizure, or following a head injury
- If the syncope occurs without warning signs in someone who may hurt themselves or faint unexpectedly while driving